What is R-Value and how do I ship cold?
R-value refers to the thermal resistance of a material. It is a measure of how well a material can resist heat flow. The higher the R-value, the greater the thermal resistance and the better the insulation provided by the material.
The recommended R-value for shipping perishable items is dependent on many factors: the product being shipped, the shipping time and method, the weather, the chosen packaging materials, and the way the refrigerated items are packed.
Products Being Shipped:
When evaluating the appropriate packaging material for perishables, you need to consider what you are shipping. Are you shipping refrigerated or frozen food? If shipping is frozen, is the intention to deliver frozen or cold? Is it intended for medicine or other materials that must be kept at a consistent temperature? Care packages that have meltable chocolate may require lower insulation than specimens being sent to a lab.
Shipping Cycle:
The entire shipping cycle should be considered when sending temperature sensitive materials. The distance you are shipping cold items must be considered. The longer temperature sensitive items are in transit the higher the possibility the temperature will rise. Another factor to consider is ground vs air shipping. Most parcel trucks (think UPS, FedEx, USPS) are not outfitted to handle small volume cold chain shipping. UPS and FedEx both offer large volume cold chain shipping solutions with refrigerated trucks, but small volumes will most likely travel by standard delivery trucks. In the summer, these trucks can become pretty warm, so you may need to consider extra insulated supplies like cold packs. During the winter, these delivery trucks are not sweltering in the sun so the amount of refrigerant may be reduced. Choosing the right shipping time and method is crucial to ensure your perishables arrive intact. An extended shipping time during the summer or in hotter climates, although it may be less expensive, may not be the right option for cold shipping due to the heat.
In addition to the actual transit time, you should prepare your temperature sensitive shipments so the receiver knows this item should be promptly opened. Consider a shipping box that is pre-printed with this information or temperature awareness shipping labels.
Packaging Materials:
What you do not want to do is place ice (frozen water) and your perishable item in a regular shipping box alone. The ice will melt, damage the corrugated box, and likely create a defect in your items. You will want to follow the following guidelines to improve your cold shipping needs:
Choose the right size - you want to ensure your perishable items fit and allow for cold ice packs. Keep in mind, when gel packs are frozen, they are not pliable like the thawed version. You do not want to leave any open space in your cold packaging. Void space can be filled in with newsprint, kraft paper, loose fill, or other material to help prevent shifting during transit and help keep a steady temperature.
Ensure your box is fully closed - you will not want to leave any gaps that allow the cold to escape. Our specially designed cartons offer FOL (full overlapping) top and bottom flaps which reduce the opportunity for gaps as well as add structural integrity to the shipping box. If you are using a standard shipping box, you want to make sure that you have sealed the top, bottom, and gaps with packaging tape.
Ship fast - choose the fastest shipping time you can. The shipping cost will of course play a part in this decision, but when in doubt try to keep shipping time to 1-2 days to avoid spoiling.
Test - when possible, send a test shipment to a friend or loved one so you can see how the package travels. This is not always feasible when shipping care packages but if you plan on regularly shipping cold products, lab testing or shipping a test package is the best way to evaluate your cold-chain packaging. When the weather changes, it is always a good idea to test again to ensure you do not need to adjust the insulated packaging.
There is no one size that fits all cold shipping applications. Packaging HERO cannot offer a guarantee on how long items will remain frozen or cold as there are so many factors that will affect these shipments.